39results about How to "Reduce heat stress concentration" patented technology

The invention belongs to the technical field of laser added material manufacturing, and relates to a method for preparing TiAl+Ti2AlNb composite materials by laser melting deposition. The laser melting deposition method is adopted to form the TiAl+Ti2AlNb composite materials; and the feeding quantity of Ti2AlNb is adjusted to achieve a pinning effect in composite material structures to improve overall plasticity of the materials. Meanwhile, circular samples are formed, and scanning paths are changed to concentric arcs to prevent the tensile stress of linear scanning paths of rectangular samples; and concentric circle openings on each layer are converted by 60-90 degrees, that is, the positions of scanning initial points on each layer are changed, so that the thermal stress concentration isreduced to prevent cracks. The heat input quantity in the forming process is controlled, and the substrate preheating temperature in the forming process is adjusted to slow down the formed metal solidification speed and cooling speed, so that the stress is released for a longer time.

The invention discloses a laser additive repair method for a titanium alloy valve rod. The laser additive repair method for the titanium alloy valve rod comprises the following steps: optimizing parameters and carrying out a multi-pass multi-layer laser additive experiment through an earlier-stage single-pass laser additive process experiment for a titanium alloy powder, and carrying out metallographic observation on a cladding layer to obtain the optimal process parameters; carrying out laser additive manufacturing printing for a performance test sample piece of the titanium alloy on a titanium alloy substrate, completing a performance test, evaluating a test result, and determining a repair process; carrying out photographing recording on an area to be repaired, and completing surface cleaning; carrying out accurate clamping on the titanium alloy valve rod, and locking the end part by a center; reserving machining allowance in an additive repair damage area carrying out coaxial powder feeding through laser, setting a scanning path to be spiral forward, enabling the left end and the right end of a starting point position to be alternating and rotate clockwise with time difference,and controlling temperature rise of the workpiece; and adopting fluorescence detection, machining according to the requirement of a drawing to restore a size, and delivering and using. According to the laser additive repair method for the titanium alloy valve rod, the requirement of safe use for the titanium alloy valve rod in a life cycle is guaranteed by optimizing the laser additive process parameters and a scanning path strategy.

The invention belongs to the technical field of metal additive manufacturing and particularly relates to a laser sintering scanning method mainly comprising division of the section of a workpiece, planning of the scanning direction, the first time of scanning, division after scanning according to temperatures, scanning according to temperature areas and other steps. According to the laser sintering scanning method, parallelogram division is conducted on the laser scanning section of the workpiece, then the temperature image of the sintering layer obtained after laser scanning is collected in real time through a thermal infrared imager, the outlines of the different temperature areas are extracted, adaptive scanning intervals are adopted for the low temperature areas and the high temperature areas in real time to form a scanning path, the problems that a large temperature gradient is formed due to temperature concentration of a certain area of a large-size thin-wall part, and residual stress is high are solved, the scanning efficiency is improved, and compactness and precision of the workpiece are ensured.

The invention discloses a negative-pressure adsorption welding device which comprises a negative-pressure producing assembly and negative-pressure adsorption plate assemblies; the negative-pressure adsorption plate assemblies comprise a bottom negative-pressure adsorption plate assembly and a top negative-pressure adsorption plate assembly; negative-pressure adsorption chambers are formed between the negative-pressure plate assemblies and the adsorption plate assemblies; the negative-pressure production assembly communicates with the negative-pressure adsorption chambers for extracting air in the negative-pressure adsorption chambers to form vacuum negative pressure; a plurality of negative-pressure adsorption holes are formed in the adsorption plate assemblies for fixing to-be-welded parts onto the adsorption plate assemblies in a negative-pressure adsorption manner to carry out welding operation when vacuum negative pressure is formed in the negative-pressure adsorption chambers. The invention further discloses a negative-pressure adsorption welding method. The negative-pressure adsorption welding device is reasonable in design, is convenient and quick to operate, is small in welding deformation and is capable of reducing working cost and improving working efficiency.

The invention relates to a cooling structure for a high-temperature rotating wheel disc. The cooling structure can be used for the rotating wheel disc of a ground fuel gas turbine, an aircraft engine and other turbine motors in the high-temperature working environment. Both the front end face and/or the rear end face of the rotating wheel disc are/is provided with a plurality of rows of heat exchanging elements distributed in the radial direction. Each row comprises a plurality of the heat exchanging elements evenly distributed along the axis of the wheel disc in the peripheral direction. The heat exchanging elements in every adjacent rows of the heat exchanging elements are distributed in a staggered mode or in an aligned mode in columns in the radial direction. By means of the heat exchanging elements, the turbulence intensity of an end face flow field of the high-temperature rotating wheel disc can be improved, and the temperature of the surface of the disc body can be further lowered through the reattachment feature that the cooling air flow bypasses the tails of the heat exchanging elements. Compared with a traditional wheel disc structure, the wheel disc cooling mode is simple in structure and easy to implement, the cooling effect of the surface of the wheel disc can be greatly improved by just additionally arranging a heat exchanging rib plate on the surface of the disc body, the wheel disc surface temperature is lowered, and the heat exchanging elements can also be used as dynamic balancing bosses of the rotating wheel disc.

At least one unit transistor is arranged over a substrate. A first wiring as a path of current that flows to each unit transistor is arranged over the at least one unit transistor. An inorganic insulation film is arranged over the first wiring. At least one first opening overlapping a partial region of the first wiring in a plan view is provided in the inorganic insulation film. An organic insulation film is arranged over the inorganic insulation film. A second wiring coupled to the first wiring through the first opening is arranged over the organic insulation film and the inorganic insulation film. In a plan view, a region in which the organic insulation film is not arranged is provided outside a region in which the first wiring is arranged. The second wiring is in contact with the inorganic insulation film outside the region in which the first wiring is arranged.

The present invention reduces the concentration of thermal stress on a burner. A gas turbine combustor receiving compressed air from a compressor, mixing the compressed air with a fuel, burning the mixture to generate a combustion gas, and supplying the combustion gas to a turbine. The combustor includes: an inner cylinder internally forming a combustion chamber; an outer cylinder covering the inner cylinder and forming a cylindrical outer circumferential flow path between the inner and outer cylinders to allow the compressed air to flow; and a burner mounted on an end of the outer cylinder, which is positioned on an opposite side to a turbine side, and facing the combustion chamber. The burner includes a cylindrical base frame including a cavity distributing the fuel, and fuel nozzles circularly arranged as viewed from the combustion chamber and connected to the cavity. When viewed from the combustion chamber, slits extending radially are formed in the base frame such that each separate the circumferentially adjacent fuel nozzles from each other.

The invention discloses a C/C composite material surface carbide derived carbon/rhenium/iridium coating layer and a preparation method thereof. The coating layer takes a C/C composite material as a matrix; a carbide-derived carbon layer, a rhenium coating layer and an iridium coating layer are sequentially arranged on the surface of the C/C composite material from bottom to top. The preparation method comprises the steps: preparing a pure Si layer on the C/C composite material matrix, carrying out heat treatment to obtain an SiC layer, carrying out chlorine etching to form the carbide-derivedcarbon layer, and sequentially depositing the rhenium coating layer and the iridium coating layer on the carbide-derived carbon layer. The carbide-derived carbon/rhenium/iridium coating layer can perfectly consider coating layer combination, coating layer matrix thermal mismatch alleviation and coating layer system high-temperature thermochemical compatibility, and has a wide application prospect.

The invention relates to the technical field of vehicle oxygen sensors, in particular to a compressive sealing method for a vehicle oxygen sensor. A sealing material used in the compressive sealing method for the vehicle oxygen sensor is prepared from h-BN or a complex of the h-BN or glass powder by molding, assembling, pressing and heating with alcohol serving as a solvent. According to the compressive sealing method for the vehicle oxygen sensor, the novel h-BN-based sealing material which can meet the usage requirements of a high-accuracy oxygen sensor on the aspects of sealing performanceand high-temperature structural stability is adopted, and the laminated structure of the h-BN and a flexible B2O3 liquid film can effectively reduce thermal stress concentration generated in a thermalcirculation process, so that the performance stability of the sealing material is improved. The h-BN-glass composite sealing material can effectively improve the airtightness, bonding strength and impact resistance of the sealing position of the oxygen sensor.

The invention discloses a display screen and a cutting method thereof. The display screen is provided with a protecting structure along a cutting area edge of the display screen; the protecting structure covers the side wall of the cutting area edge, is a multi-layer structure and can effectively protect a trepanning area edge and a grooving area edge of the display screen, thus the stress is hierarchically buffered and dispersed, impact force is neutralized stage by stage, the anti-collision capacity of a trepanning area and a grooving area of the display screen is improved, and the overall strength of the display screen is improved.

The invention discloses a radiant tube heating device with self-preheating type flue gas recirculation. The device comprises a radiant tube main body device, a combustion-supporting air preheating pipeline, a contraction opening and a formed flue gas circulation pipeline. In order to enhance heat exchange between flue gas and combustion-supporting air, a non-smooth air preheating pipeline is arranged at the tail part of the radiation pipe, so that the problems of high exhaust gas temperature and low heat efficiency of the device are solved; the gas circulation pipeline can enable a certain amount of flue gas to flow back to a combustion chamber to participate in re-combustion; the oxygen content of a combustion area is reduced by the backflow flue gas, so that the flame temperature is reduced, the stress concentration of the radiant tube is relieved while the generation of NOx is reduced, and the service life of the radiant tube is prolonged; the average flow rate of flue gas in the radiant tube is improved through jet flow generated by the shrinkage opening, so that the temperature gradient in the radiant tube is reduced, and the temperature distribution uniformity of the radiant tube is enhanced.

The invention discloses a burning chamber cover cap and a gas turbine with the same. The burning chamber cover cap comprises an outer cylinder, a nozzle cover cylinder, a diffusion panel and a fixing ring, wherein a containing cavity is formed in the outer cylinder; the nozzle cover cylinder is arranged in the containing cavity; heat dissipation holes are formed in the diffusion panel; the nozzle cover cylinder is connected with the diffusion panel; one end of the nozzle cover cylinder penetrates through the heat dissipation holes so that one end of the nozzle cover cylinder can be communicated with the outside; the fixing ring is arranged in the containing cavity; and the fixing ring is arranged on the nozzle cover cylinder in a sleeving mode so that the nozzle sleeve can be fixed to the diffusion panel. According to the burning chamber cover cap, thermal stress concentration of the diffusion panel can be reduced, and the service life of the diffusion panel is prolonged.

The invention relates to the technical field of rotor conducting strips, particularly to an induction motor rotor conducting strip and a preparation method thereof. According to the induction motor rotor conducting strip, part of the contour of the conducting strip is the same as the nominal contour of an iron core groove, a gap exists between part of the contour of the conducting strip and the nominal contour of the iron core groove, and a deformation coping structure allowing the conducting strip to deform when driven into the iron core groove is arranged. The preparation method of the induction motor rotor conducting strip comprises the following steps: S01, designing the section shape of a conducting strip, so that a part of the contour of the conducting strip is the same as the nominal contour of an iron core groove, a gap exists between the other part of the contour of the conducting bar and the nominal contour of the iron core groove, and a deformation coping structure allowingthe conducting bar to deform when the conducting bar is punched into the iron core groove is arranged; S02, designing a conducting strip preparation mold according to the section shape of the conducting strip; and S03, extruding and forming the conducting strip material into the required conducting strip through the conducting strip preparation mold. According to the invention, the conducting strip and the iron core groove are convenient to drive in and moderate in tightness; and the preparation method of the conducting strip is very simple and convenient to operate, low in cost and suitable for mass production of the conducting bar.

A crystal growth device comprises a crucible, a crucible cover and a plurality of heat reflecting rings, wherein an opening is formed in the crucible cover which is mounted on the crucible, and the crucible cover and the crucible commonly surround to define accommodating space communicated with outside through the opening; the plurality of heat reflection rings are arranged in the accommodating space and suspended on the crucible cover; every two adjacent heat reflection rings are arranged at equidistant intervals; and a first angle is formed between each heat reflection ring and the crucible cover. The plurality of heat reflection rings can deform during the heating process of the crystal device, so that each first angle is changed into a second angle. Therefore, the crystal growth device can adjust temperature gradient distribution of molten liquid surface through the arrangement of the plurality of the heat reflection rings.

The invention provides a high-performance low-carbon magnesia carbon brick and a preparation method thereof. The low-carbon magnesia carbon brick is obtained by mixing and molding a carbon-coated magnesium oxide raw material. The low-carbon magnesia carbon brick prepared by the method can be added with less or no graphite, has good thermal shock resistance and slag resistance, and can be widely applied to smelting of high-quality clean steel and ultra-low carbon steel.

The invention discloses a preparation method of a composite ZrO2-Al2O3 ceramic micro-filtration membrane. The method comprises the following steps: (1) burdening zirconia powder and alumina powder, and carrying out ball-milling; (2) adding an additive lanthanum nitrate, and carrying out ball-milling; and (3) forming a film from the milled slurry, drying and sintering. The powder components of the composite membrane layer prepared by the preparation method gradually change; the pore size distribution of the membrane layer is relatively narrow; the thickness of the membrane layer is moderate, so that the micro-filtration membrane has relatively high permeation flux and separation coefficient; the particle size collocation of the powder of a transition membrane layer is reasonable; the surface roughness of the membrane layer is improved; relatively large membrane layer pollution is not easily caused in the actual separation process; zirconia with good chemical stability is utilized in the membrane layer; and the acid and alkali resistance of the membrane layer is improved. The price of the zirconia is higher than that of aluminum oxide, but the amount in preparation of the membrane layer is relatively small; meanwhile, the service life of an inorganic membrane can be prolonged; and the composite ZrO2-Al2O3 ceramic micro-filtration membrane is better than a simple aluminum oxide ceramic membrane or zirconia ceramic membrane in the market at present in performance.